Weight really fluctuates!

It's amazing. Just a test, I've been weiging myself every day. I know that's a dangerous game, and don't plan on doing it every week this way, but just as an experiment I've been weighing myself every day after I get out of the shower. Up 3, down 2, etc. etc. etc. Is it really possible to have a 2 pound fluctuation in ONE DAY? What the hell?

(This is coming from someone who never used to own a scale. I'm a bit oblivious. The only scale I ever used to see is at WW and at the OBGYN once a year...)